[S390] vmcp cleanup

A number of small changes to vmcp:
 - Change preferred email address.
 - Use PRINT_xxx machros from debug.h like most s390 drivers, define
   "vmcp:" as PRINTK_HEADER and wrap error message at column 80.
 - Add error number to error message.
 - Update copyright, as I touched this file.
 - Small whitespace diff.
 - Use mutex instead of semaphore (Thanks Heiko for the patch)
 - Don't register debug feature on failure.
 - Check debug feature registration on init to avoid a potential oops
   on unload if the debug feature could not be registered--> 2 more
   messages.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 53 insertions, 40 deletions

diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
index 82e6a6b253eb..2f419b0ea628 100644
--- a/drivers/s390/char/vmcp.c
+++ b/drivers/s390/char/vmcp.c
@@ -1,7 +1,7 @@
 /*
- * Copyright (C) 2004,2005 IBM Corporation
+ * Copyright IBM Corp. 2004,2007
  * Interface implementation for communication with the z/VM control program
- * Author(s): Christian Borntraeger <cborntra@de.ibm.com>
+ * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  *
  *
  * z/VMs CP offers the possibility to issue commands via the diagnose code 8
@@ -22,9 +22,11 @@
 #include "vmcp.h"
 
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Christian Borntraeger <cborntra@de.ibm.com>");
+MODULE_AUTHOR("Christian Borntraeger <borntraeger@de.ibm.com>");
 MODULE_DESCRIPTION("z/VM CP interface");
 
+#define PRINTK_HEADER "vmcp: "
+
 static debug_info_t *vmcp_debug;
 
 static int vmcp_open(struct inode *inode, struct file *file)
@@ -40,7 +42,7 @@ static int vmcp_open(struct inode *inode, struct file *file)
         session->bufsize = PAGE_SIZE;
         session->response = NULL;
         session->resp_size = 0;
-        init_MUTEX(&session->mutex);
+        mutex_init(&session->mutex);
         file->private_data = session;
         return nonseekable_open(inode, file);
 }
@@ -57,37 +59,37 @@ static int vmcp_release(struct inode *inode, struct file *file)
 }
 
 static ssize_t
-vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos)
+vmcp_read(struct file *file, char __user *buff, size_t count, loff_t *ppos)
 {
         size_t tocopy;
         struct vmcp_session *session;
 
         session = (struct vmcp_session *)file->private_data;
-        if (down_interruptible(&session->mutex))
+        if (mutex_lock_interruptible(&session->mutex))
                 return -ERESTARTSYS;
         if (!session->response) {
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return 0;
         }
         if (*ppos > session->resp_size) {
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return 0;
         }
         tocopy = min(session->resp_size - (size_t) (*ppos), count);
-        tocopy = min(tocopy,session->bufsize - (size_t) (*ppos));
+        tocopy = min(tocopy, session->bufsize - (size_t) (*ppos));
 
         if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return -EFAULT;
         }
-        up(&session->mutex);
+        mutex_unlock(&session->mutex);
         *ppos += tocopy;
         return tocopy;
 }
 
 static ssize_t
-vmcp_write(struct file *file, const char __user * buff, size_t count,
-           loff_t * ppos)
+vmcp_write(struct file *file, const char __user *buff, size_t count,
+           loff_t *ppos)
 {
         char *cmd;
         struct vmcp_session *session;
@@ -103,24 +105,23 @@ vmcp_write(struct file *file, const char __user * buff, size_t count,
         }
         cmd[count] = '\0';
         session = (struct vmcp_session *)file->private_data;
-        if (down_interruptible(&session->mutex)) {
+        if (mutex_lock_interruptible(&session->mutex)) {
                 kfree(cmd);
                 return -ERESTARTSYS;
         }
         if (!session->response)
                 session->response = (char *)__get_free_pages(GFP_KERNEL
-                                                | __GFP_REPEAT  | GFP_DMA,
+                                                | __GFP_REPEAT | GFP_DMA,
                                                 get_order(session->bufsize));
         if (!session->response) {
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 kfree(cmd);
                 return -ENOMEM;
         }
         debug_text_event(vmcp_debug, 1, cmd);
-        session->resp_size = cpcmd(cmd, session->response,
-                                     session->bufsize,
-                                     &session->resp_code);
-        up(&session->mutex);
+        session->resp_size = cpcmd(cmd, session->response, session->bufsize,
+                                   &session->resp_code);
+        mutex_unlock(&session->mutex);
         kfree(cmd);
         *ppos = 0;              /* reset the file pointer after a command */
         return count;
@@ -145,12 +146,12 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         int temp;
 
         session = (struct vmcp_session *)file->private_data;
-        if (down_interruptible(&session->mutex))
+        if (mutex_lock_interruptible(&session->mutex))
                 return -ERESTARTSYS;
         switch (cmd) {
         case VMCP_GETCODE:
                 temp = session->resp_code;
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return put_user(temp, (int __user *)arg);
         case VMCP_SETBUF:
                 free_pages((unsigned long)session->response,
@@ -161,14 +162,14 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                         session->bufsize = PAGE_SIZE;
                         temp = -EINVAL;
                 }
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return temp;
         case VMCP_GETSIZE:
                 temp = session->resp_size;
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return put_user(temp, (int __user *)arg);
         default:
-                up(&session->mutex);
+                mutex_unlock(&session->mutex);
                 return -ENOIOCTLCMD;
         }
 }
@@ -180,7 +181,7 @@ static const struct file_operations vmcp_fops = {
         .read           = vmcp_read,
         .write          = vmcp_write,
         .unlocked_ioctl = vmcp_ioctl,
-        .compat_ioctl   = vmcp_ioctl
+        .compat_ioctl   = vmcp_ioctl,
 };
 
 static struct miscdevice vmcp_dev = {
@@ -194,26 +195,38 @@ static int __init vmcp_init(void)
         int ret;
 
         if (!MACHINE_IS_VM) {
-                printk(KERN_WARNING
-                       "z/VM CP interface is only available under z/VM\n");
+                PRINT_WARN("z/VM CP interface is only available under z/VM\n");
                 return -ENODEV;
         }
-        ret = misc_register(&vmcp_dev);
-        if (!ret)
-                printk(KERN_INFO "z/VM CP interface loaded\n");
-        else
-                printk(KERN_WARNING
-                       "z/VM CP interface not loaded. Could not register misc device.\n");
         vmcp_debug = debug_register("vmcp", 1, 1, 240);
-        debug_register_view(vmcp_debug, &debug_hex_ascii_view);
-        return ret;
+        if (!vmcp_debug) {
+                PRINT_ERR("z/VM CP interface not loaded. Could not register "
+                           "debug feature\n");
+                return -ENOMEM;
+        }
+        ret = debug_register_view(vmcp_debug, &debug_hex_ascii_view);
+        if (ret) {
+                PRINT_ERR("z/VM CP interface not loaded. Could not register "
+                          "debug feature view. Error code: %d\n", ret);
+                debug_unregister(vmcp_debug);
+                return ret;
+        }
+        ret = misc_register(&vmcp_dev);
+        if (ret) {
+                PRINT_ERR("z/VM CP interface not loaded. Could not register "
+                           "misc device. Error code: %d\n", ret);
+                debug_unregister(vmcp_debug);
+                return ret;
+        }
+        PRINT_INFO("z/VM CP interface loaded\n");
+        return 0;
 }
 
 static void __exit vmcp_exit(void)
 {
-        WARN_ON(misc_deregister(&vmcp_dev) != 0);
+        misc_deregister(&vmcp_dev);
         debug_unregister(vmcp_debug);
-        printk(KERN_INFO "z/VM CP interface unloaded.\n");
+        PRINT_INFO("z/VM CP interface unloaded.\n");
 }
 
 module_init(vmcp_init);
diff --git a/drivers/s390/char/vmcp.h b/drivers/s390/char/vmcp.h
index 8a5975f3dad7..6a993948e188 100644
--- a/drivers/s390/char/vmcp.h
+++ b/drivers/s390/char/vmcp.h
@@ -12,8 +12,8 @@
  * The idea of this driver is based on cpint from Neale Ferguson
  */
 
-#include <asm/semaphore.h>
 #include <linux/ioctl.h>
+#include <linux/mutex.h>
 
 #define VMCP_GETCODE _IOR(0x10, 1, int)
 #define VMCP_SETBUF _IOW(0x10, 2, int)
@@ -26,5 +26,5 @@ struct vmcp_session {
         int resp_code;
         /* As we use copy_from/to_user, which might     *
          * sleep and cannot use a spinlock              */
-        struct semaphore mutex;
+        struct mutex mutex;
 };